Ethan J. Halpern MD, Presenter: Research grant, Koninklijke Philips Electronics NV Research grant, Lantheus Medical Imaging, Inc Equipment support, Toshiba Corporation

Daniel Dean Sackett MD, Abstract Co-Author: Nothing to Disclose

Flemming Forsberg PhD, Abstract Co-Author: Equipment support, Toshiba Corporation Equipment support, Siemens AG Research collaboration, General Electric Company Research collaboration, Ultrasonix Medical Corporation Research collaboration, Toshiba Corporation

Leonard G. Gomella MD, Abstract Co-Author: Consultant, GlaxoSmithKline plc

Edouard J. Trabulsi MD, Abstract Co-Author: Nothing to Disclose

To evaluate detection of prostate cancer using contrast-enhanced ultrasound with flash replenishment maximum intensity projection (MIP) MicroFlow Imaging (MFI).

209 patients referred for prostate biopsy were evaluated by transrectal US using a PVT-661VT endocavitary probe on the Aplio scanner (Toshiba America Medical Systems, Tustin, CA). The microbubble agent Definity (Lantheus Medical Imaging, N Billerica, MA) was diluted with saline to a concentration of 49.4uL/mL and infused at 4mL/min. MFI is a flash-replenishment technique that uses high power flash pulses to destroy bubbles, followed by low power pulses to demonstrate contrast replenishment and depict vascular architecture with a MIP display. Up to 6 targeted biopsy cores were obtained from areas of abnormal vascular enhancement or morphology on MFI, followed by a systematic 12 core biopsy protocol.

Enhancement of prostatic vessels was observed in all patients. A positive biopsy for cancer was found in 339/3427 cores from 82/209 (39%) of subjects. Positive biopsies were obtained in 199/2508 (7.9%) of systematic cores and 140/919 (15.2%) of targeted cores. Among patients with a positive biopsy, the odds ratio for a positive core with targeted biopsy versus systematic biopsy was 3.0 (95% CI: 2.2-4.1, p<0.001). On a per-patient basis, cancer was more frequently detected by systematic biopsy (n=76) relative to targeted biopsy (n=51; McNemar Chi-square = 7.76, p=0.008). Among the 76 patients detected by systematic biopsy, those 44 patients with a positive targeted core demonstrated an average of 3.7 positive systematic cores while those 32 patients who were missed by targeted biopsy demonstrated an average of 1.6 positive systematic cores (p<0.001). Mean percentage of systematic biopsy core involvement was 32% among patients with a positive targeted core, compared with 17% among patients who were missed by targeted biopsy (p<0.01). Higher grade cancer (Gleason score >6) was more common among patients with a positive targeted biopsy (48% versus 16%; p=0.005).

Targeted biopsy of the prostate using contrast-enhanced MFI selectively detects high volume cancer with Gleason scores of 7 and higher. Low volume cancer with a Gleason score below 7 is less frequently detected by MFI targeted biopsy cores.

MFI imaging of the prostate identifies high volume/grade cancers which are most likely to be clinically significant.

Halpern, E, Sackett, D, Forsberg, F, Gomella, L, Trabulsi, E, Flash Replenishment MIP Imaging with Contrast-enhanced Ultrasound Identifies High Volume/High Grade Prostate Cancer.  Radiological Society of North America 2010 Scientific Assembly and Annual Meeting, November 28 - December 3, 2010 ,Chicago IL. http://archive.rsna.org/2010/9001021.html